Chemical Engineering April 2019 - 9

Nanostructured catalyst converts CO2
to ethanol electrochemically
R
educing carbon dioxide to useful
fuel molecules is a highly desired
objective, but is difficult because
the required reactions are energetically
unfavorable, and a cost-effective
and robust catalyst for the reduction has
been elusive. Now researchers at Oak
Ridge National Laboratory (ORNL; Oak
Ridge, Tenn.; www.ornl.gov) may have
found such a catalyst - nanostructured
carbon with embedded copper nanoparticles
- that can convert CO2 to ethanol in
an electrochemical cell.
" The reaction between CO2 and the
catalyst is kind of a reverse combustion
process that takes place in a modified fuel
cell, " explains Adam Rondinone, ORNL
senior scientist. " It offers a pathway for
using renewable electricity to make carbon
fuels from a greenhouse gas. "
In March, the ORNL catalyst and electrochemical
cell technology was licensed by
ReactWell LLC (New Orleans, La.; www.
reactwell.com) for further development,
and inclusion in industrial process units.
" The catalyst is a heavily textured graphene
with copper nanoparticles lodged into the
surface, " says Rondinone. " The graphene
forms carbon 'nanospikes' that orient the
CO2 molecules to influence the reaction
mechanism. " The catalyst material forms
localized electric fields, which focus the
electrochemical reactivity so that the reaction
pathway forms the desired products.
At the cathode of the cell, the catalyst
reduces CO2 to CO on the catalyst surface.
CO is a reaction intermediate that
dimerizes and combines with hydrogen
from water (which is co-reduced in the
cell) to form ethanol. Oxygen is evolved
at the anode.
ReactWell CEO Brandan Iglesias says
the first application for the licensed ORNL
technology is making ethanol for alcoholic
spirits, because it is a low-volume,
high-margin market, he explains, and is
attractive to enter with this novel electric
alcohol technology. Eventually, the technology
would be used at petroleum refineries,
where CO2 from exhaust gas could
be captured and converted into ethanol to
upgrade transportation fuel stocks.
photocatalytic activity (PCA)
and self-cleaning properties. It
has selective spectral absorption
in the ultraviolet range, but
is transparent to visible light.
When titanium is exposed to
ultraviolet (UV) light, it breaks
down water vapor in air to
produce free oxygen radicals,
which attack organic matter,
such as the membranes of
bacterial cells.
Krumdieck and her colleagues
grow TiO2 coatings
directly on
stainless steel
using a pulsed chemicalvapor
deposition (CVD)
technique she developed.
An ultrasonic atomizer is
used to make a fine mist of
a TiO2 precursor, which is
pulse-sprayed into the CVD
chamber. This technique increases
the rate at which the
TiO2 crystals grow, resulting
in a 10-µm-thick coating
with an interesting structure:
vertical columns of stacked
15-20-nm-thick single crys(Continues
on p. 10)
CHEMCAD
process simulation
software can't
mix cocktails.
But it brings your creative
ideas to life.
CHEMCAD provides rigorous,
first- principles based simulation for
continuous and transient processes.
It is also backed by experienced
and responsive support engineers.
Contact us today for a free trial.
chemstations.com/mix1
CMS-6752 Brand Awareness Ad CE Half Page v1.0.indd 1
For details visit adlinks.chemengonline.com/73853-09
3/4/19 10:36 AM
CHEMICAL ENGINEERING WWW.CHEMENGONLINE.COM
APRIL 2019
9
http://www.ornl.gov http://www.reactwell.com http://www.chemstations.com/mix1 http://adlinks.chemengonline.com/73853-09 http://WWW.CHEMENGONLINE.COM
Chemical Engineering April 2019

Table of Contents for the Digital Edition of Chemical Engineering April 2019
